Public address (PA) and voice annunciation (VA) systems stream live audio (multimedia) announcements across a large number speaker nodes distributed in a building. Speaker nodes are triggered to start announcements for emergency evacuation, mass notifications, and office announcements, or to play background music. All speaker nodes are wire connected with a centralized monitoring and announcement panel (voice control panel).
Unfortunately, speaker nodes deployed in such a system require multiple pairs of wires from the central panel to both power the device and to receive audio data. This makes the network deployment slow and costly. Current systems are hard-wired and can create zones only during deployment, which cannot later be changed if the building is renovated. Also, testing of such a system requires the entire building to be evacuated. The maintenance cost of such a system is high as large lengths of wires that are required to cover the building have to be monitored and replaced. In some systems, speaker nodes can communicate wirelessly using Bluetooth or Wi-Fi, but they are restricted to one hop, and are used as part of a wired system, not as a standalone system to cover the entire building or part of the facility.